A device of this kind is taught in the applicant's own Norwegian Patent 171,349. This device consists of a balance body which is attached to a U-shaped band, which in turn is attached to a hairband or similar. A spring or similar is located between the legs of the U-band so that the balance body will tip forward when the head is moved too far forward and out of a correct head position. When this happens, a signal will be given to indicate that the user has assumed an incorrect sitting posture.
This device functions extremely well under qualified guidance, but nevertheless encumbered with certain weaknesses. For example, the device is rather large and lumpy and projects quite high above the user's head. This means that the device could easily be torn off the head if the user knocks into a low door frame or similar.
Further, the device has proven to be somewhat difficult to calibrate and is very sensitive to deviations from the correct calibration. Moreover, it is difficult for the user to perceive when the balance body of the device tips forward, and he or she is therefore dependent on either a mirror or having another person present as an observer.
Moreover, the device will only indicate incorrect head position when the head is tipped too far forward. It will not indicate an incorrect head position when the head is tipped sideways. SUMMARY OF THE INVENTION
In order to eliminate these disadvantages it is therefore proposed to design the device as described in the characterising clause of independent claim I below, and also in the subsequent dependent claims.